waterdamagequotesSewage backup and drain overflow: what changes
Everything about a sewage event is different from a clean water event, and almost none of the difference is in the drying. It is in what can be kept.
Everything about a sewage event is different from a clean water event, and almost none of the difference is in the drying. It is in what can be kept.
Treat it as a health hazard first and a claim second. Keep people and pets out of the affected area. Do not run air movers across it — moving contaminated air around a house is the opposite of what you want. Ventilate to outside if you can and close the affected rooms off from the rest of the building.
Which claim it is depends on what pushed it back
This is the part that decides the excess and, in a flood event, whether it is covered at all.
| What happened | Provision | What it means |
|---|---|---|
| A blockage in your own drain — roots, wipes, a collapsed section — and the lowest fixture in the house overflowed | reg 19(1)(a)(vi) |
Overflowing of fixed apparatus and fixed pipes. Standard escape of water, subject to any sewage sub-limit in the policy |
| The water authority’s main surcharged in heavy rain and pushed back through your connection | reg 19(1)(a)(xiv) or reg 34(1) |
Storm, unless the surcharge was driven by water that escaped a watercourse — in which case it is legally a flood and the flood position applies |
| Flood water entered the property and the sewer surcharged as part of the same event | reg 34(1) |
Flood, with whatever flood excess the policy carries |
The middle row is where the money is. A surcharged sewer in an ordinary heavy-rain event is not flood under reg 34(1) — the water never left a lake, river, creek, watercourse, reservoir, canal or dam. If an insurer applies a flood excess to it, that is worth challenging, and the flood definition page sets out why.
The first row is the most common and the least appreciated: a blocked drain in your own property is an escape of water from fixed pipes, full stop. Roots in a clay sewer line are an Australian suburban constant and they produce a textbook reg 19(1)(a)(vi) claim.
What Category 3 does to the scope
The rule Australian restorers work to is that porous materials that have been in Category 3 water are removed and disposed of, not dried. In practice that means:
| Removed and disposed of | Cleaned, sanitised and kept |
|---|---|
| Carpet and underlay | Concrete slab, once cleaned and dried |
| Plasterboard to above the water line, commonly 300–600mm | Structural timber, if sound and properly treated |
| Bulk insulation in affected walls | Sealed hard flooring, tiles |
| Particleboard flooring and cabinetry bases | Glass, metal and sealed hard-surface joinery |
| Soft furnishings and mattresses that were wetted | Machine-washable textiles, at temperature |
| Timber skirtings and architraves, usually | Solid timber furniture, after cleaning |
The plasterboard row is the one that surprises people. It is cut horizontally at a line above the highest point of contamination — a “flood cut” — and the wall cavity is then cleaned, treated and dried before it goes back. This is why a sewage job produces a reinstatement bill that a clean water job does not.
The equipment changes too
Drying equipment is the same, but two things are added:
- HEPA air filtration. Scrubbing the air in the containment zone rather than blowing it around. On the published rate card this site reproduces, HEPA filtration is $80 per unit per day with a 3-day minimum, excluding GST — and on a sewage job it is not optional.
- Containment and negative air. Plastic barriers and a pressure differential so that air moves into the affected zone and out through filtration, not into the rest of the house. This is what stops a localised contamination event becoming a whole-building one.
| Line item | Published rate | Basis | Published by |
|---|---|---|---|
| Emergency call-out | from $149 | per attendance, excluding GST | QLD Flood Restoration |
| Carpet water extraction, first hour | from $250 | first hour, excluding GST | QLD Flood Restoration |
| Carpet water extraction, each hour after the first | from $90 | per hour, excluding GST | QLD Flood Restoration |
| Carpet dryer (air mover) hire | from $69 | per unit per day, minimum 3 days, excluding GST | QLD Flood Restoration |
| Dehumidifier hire | from $149 | per unit per day, minimum 3 days, excluding GST | QLD Flood Restoration |
| HEPA air filtration unit hire | from $80 | per unit per day, minimum 3 days, excluding GST | QLD Flood Restoration |
What those rates do not include, and what actually dominates a sewage invoice: demolition labour, waste disposal, antimicrobial application, containment materials, and reinstatement. This site does not publish figures for those, because no Australian company was found publishing them.
Get a Category 3 scope, not a drying quote
Ask whoever attends what they will remove, not just what they will dry.
The health guidance
NSW Health’s mould factsheet is the most practical Australian government document on cleaning contaminated surfaces, and three parts of it apply directly here.
NSW Health, Mould factsheet · current as at 20 December 2022, read 20 September 2026
Second line, for mould that will not come off an item you cannot discard. NSW Health recommends PVC or nitrile rubber gloves, safety glasses and safety shoes, and good ventilation while you use it.
NSW Health, Mould factsheet · current as at 20 December 2022, read 20 September 2026
Absorbent materials such as carpet, once mould-contaminated.
And the one that governs the whole job: NSW Health, Mould factsheet — Which is why a drying record matters more than a surface clean, and why an insurer that has paid to dry a building properly is not usually arguing about the mould that did not grow.
For a sewage event the cause is usually a drain that will do it again. Root intrusion, a collapsed section, a bellied line. Whatever is cleaned up, the drain investigation is the part that stops it recurring, and a CCTV drain inspection is worth asking for before the reinstatement goes back in.
Temporary accommodation
Most Australian home policies include temporary accommodation where the home is uninhabitable, and a sewage event across living areas frequently is. It is a separate benefit with its own limit and it is not paid unless it is claimed. Claim it on day one, in writing, and keep every receipt.
If money is the immediate problem, General Insurance Code of Practice, paragraph 64: where you demonstrate urgent financial need, the insurer fast-tracks the assessment and pays an advance amount within 5 business days.
Get a sewage cleanup quoted
Cause already selected, so whoever calls knows to bring containment and filtration rather than two fans.
Your enquiry is ready to send
Here is what happens after you submit:
- Your answers go to restoration companies that advertise for your postcode.
- No more than three of them may contact you, using the details you gave.
- You decide who, if anyone, you use. You are committed to nothing, and this does not lodge, alter or affect an insurance claim.
We are not a restoration company and we do not attend, assess or repair anything.
Common questions
Is a sewage backup covered by home insurance?
It depends on what pushed the sewage back. A blockage or failure in the building's own fixed drainage points at reg 19(1)(a)(vi) of the Insurance Contracts Regulations 2017. A main surcharged by water that came out of a watercourse points at flood under reg 34(1). Many policies also carry a separate sewage or waste-water clause with its own limit.
Can carpet be saved after a sewage overflow?
Generally not. Sewage is grossly contaminated water and the standard approach is removal and disposal of porous materials rather than drying them. NSW Health's position is that absorbent materials such as carpet may need to be professionally cleaned or replaced where they are mould-contaminated.
What is the difference between grey water and black water?
Grey water is waste water without faecal contamination -- a washing machine discharge, a shower waste. Black water contains it. Australian restorers usually describe these as Category 2 and Category 3, and the practical difference is whether porous materials can be dried or have to be removed.
Do I need to leave the house?
If sewage has crossed a large area, or has entered rooms where people sleep or food is prepared, assume yes until a restoration company says otherwise. That is also a temporary accommodation claim under most policies, and it is not paid unless it is claimed.
Why does a sewage job cost more than a clean water job of the same size?
Because almost none of the cost is drying. It is removal, disposal, containment, negative air pressure, antimicrobial treatment and reinstatement of everything that came out. The drying equipment is the same; the work around it is not.
Sources cited on this page
- Insurance Contracts Regulations 2017 (Cth)
- Insurance Contracts Regulations 2017 (Cth) reg 19(1)(a)(vi)
- Insurance Contracts Regulations 2017 (Cth) reg 34(1)
- NSW Health, Mould factsheet
- QLD Flood Restoration, published equipment hire and extraction rates
- General Insurance Code of Practice (2020 Code, October 2023 update)
Every figure above was read from the source it is attributed to on 20 September 2026. How we check this.